A Question about keys

[trust24]

I know there is a thread somewhere about this but im just confused

Can somone explain it to me in a really simple way what makes up a key, how you determine what key somthing is in. For example is a key like a scale where there are certain notes and you can pick whichever note you want and use that as your starting note

Please help

[bass player 48]

Yes, a "key" is like a scale.

In the "key" of C (major) you can think of a C major scale.

The 1 chord is a C major chord (spelled C E G) and the 2 chord is a D minor (spelled D F A) and so on...

Often times the first note you play, and / or the last note, will give you a clue as to what key you are in (if you play a C note on bass, and the guitar plays a C Maj chord - both to start and finish the song, you're probably playing in C)

See also "the chord that feels like home" in the tune.

[Jim Carr]

Home, yes.

Key is one of those things that give us the heard musical sensation of tonal center. Cadence, scale, mode, drone, pedal tone, root movement/repetition, and no doubt others belong on that list as well.

A tonal center is a note (represented by an instance of a note in any octave) that seems to be the "most important note" in the sense of being "a chord root at rest" or the most resolved/ending chord root. It's a root/pitch that need not be moved to any other ptich to provide the musical sensation of completion, assuming the right position in a phrase. It often appears at the end of a composition or end of a larger formal section.

A tonal center is a perceptual "fact" in that most listeners will agree on which is the most important pitch (or even chord root) heard in a given piece.

I am leaving out the possibilities of a piece having no tonal center, an ambiguous tonal center, or one that shifts so frequently that tonal center is meaningless.

Determining key or tonal center in real time is highly reliant on your own perceptual tools and not something that a verbal description can easily or practically convey.

The thing that allows a tonal center to occupy the most important perceptual location in most pieces is root movement to an accented beat at the end of a phrase. This is usually where a major or minor triad occurs with that pitch as its root. Since a lot of rock and other popular music avoids traditional harmonic cadences, it is a tall order to describe rules for finding tonal center in such music. However, since root movement of major or minor chords by major seconds, major or minor thirds, or descending perfect fourths often has replaced dominant/tonic V-I cadences, it is the rhythmic and phrase structure context that points to the tonal center.

I've avoided the term key, because to me it implies the major/minor diatonic system, which a lot of blues, rock, and other "vernacular music" doesn't really embrace. Using the term Key in the more general sense of tonal center seems fine for performance related issues and basic theory.

[mambo4]

As mentioned, yes a key is like a scale. A piece of music in C major will usually only use the notes of a C major scale.

As mentioned, the root of final chord of a song is a usually good indicator of the key, tho certainly not always.

I say usually because there are almost always accidentals (notes outside of the key) or modulations (entiore chord progressions outside of the key) in most music. And it is fairly common to start/end on a note/chord that is not the "One" of the key.

I also say usually because some genres bend this expectation, for example "blues in the key of A" will not strictly adhere to the notes of the A major scale, because the Blues genre is not diatonic (ie, not based purely on the major scale and its modes)

Of course the most iron clad way is to look at the sheet music and find the key signature

[Bruce Lindfield]

Originally Posted by trust24

I know there is a thread somewhere about this but im just confused

Can somone explain it to me in a really simple way what makes up a key, how you determine what key somthing is in. For example is a key like a scale where there are certain notes and you can pick whichever note you want and use that as your starting note

Please help

No - you cannot pick any note from a notional key and use that - you have to play something that relates to the chord structure being played at the time!

[mambo4]

Bruce speaks wisely, and is pointing out something crucial that is missing from earlier replies.

Knowing what key you are in and how to play within that key is somewhat useful. But knowing what the chords of the song are, and how to play under those chords, is 1000x more practical for bassists. Most of your theory exploration should be aimed at relating the information to chords and chord progressions, and how to play to them.

[RDUB]

Big +1!

[trust24]

Right ive decided im going to take lessons, although i get what your saying i think itll be easier having a teacher who can tell me